Direct Exception - Unable to connect to server

I took over a site and I'm still trying to understand the ExtJs code. Its version 3.4.0 and every so often I get these popups titled Direct Exception with the text 'Unable to connect to the server.' I'm using the ext-all-debug.js file but I'm still not getting any details on what the error is exactly. I really don't know what call its making when it gets this message because it finishes the action I pressed OK for but then a second or two later it pops up with this message. How can I get more detail on where its coming from and what's happening? The action is getting back to the code and doing my inserts but its like when it comes back its showing these message. How can I get more detail?

Did you open the browser's dev tools and look at the network tab to see the requests. You can see the requests and maybe see which API fails and track down in your code to see where that particular API is being called.